For cash registers and the like it is necessary to form an internal record, particularly where data processing equipment is used with the cash register. It is often highly desirable to form a printed ticket to be dispensed with the goods, and typically they must be printed in multiple copies. For instance, one copy can be given to the customer, another copy retained by the sales clerk for purposes of calculating his commissions, and another ticket turned in with the cash register receipts at the end of the day to enable balancing of the cash register with the actual cash receipts.
It is possible to utilize straight alphanumeric characters in the form of type written characters. However, this requires an unduly complex press head. A print head the numeric characters only is relatively simplified by it still requires a type of rotating wheel or typing keys. The present invention is directed to an alternate construction which is believed to be simplified in that every number is converted to a dot matrix, and the most convenient matrix for the present invention is a seven by five dot pattern. This takes advantage of design techniques already known including BCD formatted data which is converted to a format utilizing seven segments. Seven segment formats are known for LED displays and they are incorporated in the present apparatus. The apparatus utilizes seven parallel needle printers driven by solenoids. The seven solenoids operate in timed sequence with signals provided through a dot keyer which amplifies a driving signal from a seven by five matrix gate arrangement. The present invention is advantageous in operation in that it is able to strike quite hard using needle printer mechanisms. It is able to strike hard and therefore print through multiple copies using impact paper. Moreover, it forms characters which are easily read. Accordingly, the apparatus is advantageous in the formation of numeric characters on a ticket.